Excel 2016: double-clicking on a file opens two Excel windows

Below works in upto Excel 2013. See whether it helps in Excel 2016 or not.

Option 1 -  Please look into C:\Users\User_Name\AppData\Roaming\Microsoft\Excel (replace user name with your user name, you can directly reach here by copy and pasting following without quotes in Explorer address bar - "%appdata%\Microsoft\Excel\XLSTART") and see if is contains few files / folders. Move those files to some other location (i.e create a backup of those files / folders and delete all files / folders from here). Hence, make Excel folder blank.

Now open the file and see if the problem disappears or not. 

Note - to find Excel path, you need to find XLSTART path. Excel folder contains XLSTART folder in itself.

1. Open Excel
2. ALT+F11
3. If Immediate Window is not visible, type CTRL+G. Same can be also be accessed through View > Immediate Window
4. Type "? application.StartupPath" without quotes and press enter
5. You will have your path below.

Option 2 - One user reported - I was also having this intermitttent issue and I found out that it is related to the Explorer preview pane. It only occurs if the preview pane is open and the xls file was never selected. Double clicking on the xls file opens 2 instances of excel (one empty). The second instance is probably the one used to show the file in the preview pane. Once the file have been seen at least once in the preview pane(during the current session)  the issue does not occurs, anymore (until reboot and/or some time has elapse. I guess there is some sort of caching). TURN OFF THE PREVIEW PANE IN WINDOWS EXPLORER. If the preview pane is a must, you can right click and 'open' the document and not get the issue.

Option 3 - Sometimes, add-ins can cause problems. To determine, if add-in is a problem start Excel in safe mode and see if problem has gone away. If yes, then start Excel normally and disable add-ins one by one and start Excel again every time you disable an add-in to determine the culprit add-in.

To start Excel in Safe Mode -

Hold CTRL key and click on Excel icon

OR

In the Search Box above Windows icon, type "Excel /s" without quotes and enter.

Option 4 - Review the KB articles - https://support.microsoft.com/en-us/kb/2758592 and https://support.microsoft.com/en-us/kb/2779852

Option 5 - How to prevent files from opening automatically in Excel - http://support.microsoft.com/kb/826922/en-us

Option 6 - Login to Windows with a new user profile and run Excel.

XLSTART contains the personal macro workbook. If you move it, macros are not available anymore, but without the personal macro workbook, the issue of opening 2 windows has disappeared

I did the following:

Once in Excel with the issue gone, I created a macro, saved it to (a newly Excel created) macro workbook.

Now opening Excel or an Excel file, the issue of the 2 windows is still gone.

As I had copied all my Excel macros to a word file, I copied them into the new personal macro workbook. The issue of the 2 windows when opening an Excel file is still gone.

So it seems to me that the issue is in the personal macro workbook as a leftover from the previous office version. Once I created a new macro workbook and filled it with my macros, the issue does not reappear

SORRY, I OVERLOOKED THAT IN THIS THREAD SOMEONE HAD ALREADY PROPROSED THE SAME SOLUTION

This bug was fixed some time ago but a recent Office 2016 update has brought the problem back and a few others with it. Why, why, why can't they get it right???

It's clearly a bug in Excel 2016. I hope that Microsoft will fix it, but that might take a while (updating Office is a very bureaucratic process).

Hans,

    Thank you for that information.  Trial and error narrowed it down to the Xnumbers Add-in.  This was not a problem with previous versions.  And, in 2016, that add-in is also not properly installing it's toolbar.  Unfortunately, there does not seem to be any support for that add-in, so it is either a matter of living with it, or my trying to figure out the issues.

Do you have any ideas as to what is causing these "blanks" to appear.  I notice that with my personal xlam file, a blank book or sheet flashes, but then disappears.  Again, this is something that is happening in 2016, and was not a problem in 2007

Add-ins can cause the same problem.